A surprisingly new study revealed that thunderstorms could trigger an asthma attack, as shown by the rise in the number of emergency visits for seniors, days before a thunderstorm.

The research letter published in JAMA Internal Medicine on Monday stated that there was a rise in emergency visits in 65 years and older. However, the study's author Dr Anupam Jena, Harvard Medical School's associate professor of health care policy, noted that it also poses danger to the younger population who are suffering from severe respiratory illness.

Using Medicare data, researchers found that visits to the emergency department peaked one day before the thunderstorm. They approximated it at 1.8 additional visits per million beneficiaries. They also noted that the visits did not happen on the day of the actual thunderstorm when rains were coming down, nor did they pay the hospital a visit after the thunderstorm. In fact, the rate of visits to the ER went down after the storm.

The study specifically looked at insurance claims linked to respiratory-related issues between January 1999 to December 2012. The Medicare data was then compared with the U.S. National Oceanic and Atmospheric Administration atmospheric and lightning data.

Jena mentioned that the data showed that the particulate matter in the air starts rising on days that lead to the thunderstorm. This particulate matter is a mixture of smoke, dirt, and dust and are very fine in size, which could not be seen by the naked eye. They could easily be inhaled due to their size, which is 2.5 micrometers or less. Once inhaled, they can enter the lungs and disrupt the respiratory process.

This size is generally referred to as PM 2.5. To paint a better picture of how big these particulates are, the human hair is said to be 30 times larger than this.

asthma Photo: Reuters/Kim Kyung-Hoon

Based on census data used by researchers, the study estimated that there are approximately 37.7 million Americans aged 65 and older. Within the 14-year period of the study, they ascertained that there were additional 52,000 emergency room visits from this age group because of respiratory distress. The visits started around three or more days prior to a storm.